You just cannot do that with a pure regex and, even with an extended regex package, it is at least very difficult and likely to be unreliable.

You really need a parser to do this sort of things. See if you have a parsing library in VBA, or you can write a very simple parsing tool which could, for example, read characters one by one and set a flag to true when it meets the first quote and to false when it meets the next one (and so on). Then you do the replacements when he flag is true.

Another way is to split the line on quotes into an array, make the changes in array elements that have an odd subscript, and then reconstruct the line. This is an example in Perl at the command line: